parkumi

Parkumi is parko, a park, plus -um-, plus the verb ending. And it means to park a car.

That leap is the whole point of -um-. Every other Esperanto affix has one fixed meaning: -ej- is the place, -il- is the tool, -ist- is the person. -Um- is the official exception, defined as having no meaning at all. It signals only that the new word has something to do with the root, and convention decides what. So a park becomes parking, and you simply have to know.

The -um- family this course has already taught is now big enough to name:

• butikumi - to go shopping, from butiko, a shop
• brakumi - to hug, from brako, an arm
• gustumi - to taste, from gusto, taste
• cerbumi - to puzzle over, from cerbo, a brain
• mastrumi - to keep house, from mastro, a master
• plenumi - to fulfil, from plena, full

Six roots, six unrelated jumps, one suffix. There is no rule connecting them, and pretending otherwise would be the dishonest way to teach it: these are vocabulary, learned one at a time. The -um and word formation article explains why a planned language needs an overflow pipe like this, and what it costs.

The noun is parkumado, parking as an activity, and a car park is parkumejo: -um- and -ej- stacked, which is as far as this word can reasonably be pushed.